I have some smudges on my monitor (NEC 27") and have a hard time cleaning it properly. I've used an antistatic cloth and some breath in my attempt to clean the screen. Still with a black screen/image you can still clearly see the marks. What do people use to clean their screens? What liquid and wipes, if any?

If you reuse the cloth or let your fingers touch stains will reappear. Here's the technique I've used for years:

Brush away dirt with a fine brush.Clean with Cleaning kit liquid with lint-free cloth (optician's liquid is good)Use another cloth to wipe dry.For the 'stains' use a small piece of newspaper and wipe with circular motions. If you don't like the newspaper idea, wear surgeon's gloves instead.If you come into contact with the monitor directly, do everything again - oil spreads.This way, when clean, there isn't a single spot visible against black, from all angles. Never touch the monitor directly, always use the sides to move.

I find an automotive polishing-grade microfiber cloth (available at Walmart) very lightly dampened with distilled (deionized water) works well, without leaving smudges or scratches. The goal is to use as little moisture as possible, with the cleanest, softest cloth.